1. Field of the Invention
This invention relates to corrosion inhibitor compositions and is particularly concerned with multicomponent inhibitor formulations capable of protecting ferrous metals against attack by corrosive acids in high temperature environments.
2. Description of the Prior Art
The corrosion of oil field tubular goods and similar equipment by hydrochloric acid solutions and other corrosive materials used in well workover and stimulation operations is a longstanding problem in the petroleum industry. The use of inhibitors to combat such corrosion is conventional. The materials suggested in the past for use in such inhibitors include various acetylenic alcohols, fluorinated surfactants, quaternary derivatives of heterocyclic nitrogen bases and halomethylated aromatic compounds, formamides, and surface active agents, alone or in combination with other materials. U.S. Pat. No. 2,814,593, for instance, discloses compositions of this nature. Tests have shown that certain of these earlier compositions are reasonably effective for inhibiting the corrosion of ferrous metals in shallow wells where temperatures are relatively low and conditions are not severe. In deeper wells where temperatures of 300.degree. F. or higher are apt to be encountered, it has been found that corrosion rates tend to be exceptionally high and that many of the compositions advocated for use in the past are inadequate. Efforts to develop improved inhibitors which will be effective under these more severe conditions have not heretofore been as promising as the compositions of the instant invention.